Trailer suspension unit



March 28, 1950 M. D. SULLIVAN 2,501,974

TRAILER SUSPENSION UNIT Filed June 28, 1948 2 Sheets-Sheet 1i A \HIIIIHIIIIIHHHIIIIIIIIIIIIHIIIIHHlfl I8 I 4 \uveu'n'ow. E MATHEW D. Suuwm, I

Aw'ronnews March 28, 1950 M. D. SULLIVAN 2,501,974

TRAILER SUSPENSION UNIT Filed June 28, 1948 2 Sheets-Sheet 2 5 b A W f A l A? 5 Tm=4n 1a 9 Irwin-reg MATHEW D. SUM-WAN Wlllunum Anon-u EYS Patented Mar. 28, 1950 omen:

" inveiwe'n'" retest) a "trainer s'usbension structurewhilevery useful in connection with trailers which "are'draw'n at thebacKs of motorfyehiels, is notj'ne'cessarily restrictedin ujse tothebneuse named, but may be 'ofamo're g'hjeifal application.

Inth e' drawing of traiiers over the road, and

iii} many "other types "of" Vehicles, the wheels whichcaifiji such Vehicles -are subjected to differiiie" oi'i'ditioris" n" accor-uariee "with the varying cond tioiis'of'the road and should have an inaeee'aeaee infmovmen'tas much as possible. eachwhei isniaae'whbu'y indep'endentin itsjnioiiritin'g lipofi arrame with which it is'ico'nlfect'd; the stability of the vehicle 'is detrimentally affected I It is an oljo'jekfli aiidburbos'e of the present inviitiohte "provide a practica simr'ile, novel and ve'r'i' useful wheel mounting and connection, and with 'a'vefy nractica'l and 'userm sprin suspension thereof in which each of the wheels at "one side oif'a' Eanerrrameor other vehicle'fr'ame, has a large measure of independence of movement withreference to the tofiioo's'ite'wheet'which is use 1 arid ytj is ifitrboliriedted by a' yieldiltl g C011- chassis members" '1. aifd fthecrosshar 2, preferablx' area: C0 dchannelfforni. From th'e I I ossb ai' zjtoward each ehd of the" bar, I i wardly'a short distance fromfeach'of 'tlie ideira'memeinbers I, a'short channel b'a'r 3 is' locatedand welded at its front en ime bar 2; ektendingrearwardly there item a short chance; and thehextendin'g "reap war'dly ahdoutwardlyas at 312', beingwelded at its'rearefid to the adjacent sidef frame member l} pnten eiit efids' be'tweeh the'u'pper flanges 3 a'r'ild' their extensions 3a. It is ee eiielet y Sshr ale f Weldifig Q 7 hither permanent conhe'ctlonand bridges' th'e gap b'e i tween said"uhhrvfiaiiges of said members I and and the adjaceht are? and 15. em i Place becoming-raj permanent gpart of -the frame struc- 'riction which" is of sentient resistancesu ch tha S Ctlil thereon 1S substantiall trial n- 'ta ed. Theelimination of undue" strains'upoh theconnecting 'parts'bet V is obtained and a particularly sert able snring susfiiisi on uniti' orltrailer framesaridother veh'icle frames is prov dejd.

Like reference characters-'refer to like parts i h i e t v es 91t iega n the "sections are taken looking in the directions indicated by the arrows.

In the embodimentshbwiia chassis'frame hav ing two spaced apart chassis side frame members Lwhich in use are flocated generally horizohtaljmay haveth'eir forward portions laten- "j igejand'meetand be permanently con'rieeted together; Of 'course,"'the jsp'eci 'ic detail 'o'ffthe frame structure so "far "as the chassis side Tframe 'fnembers "may b'e'"conc'ernedis not essential to this invention-.--Adjacer1t -the-'-places on the frame where the wheels areto be located, a horiaontal crossbar 2 is providd;'being weldedfat'its t the stability "of the frame or any Stipe'ru eh qs a tfi a se 'ire @5611 c the le .bushi syt pr je ing-b y nd c iend ther M einn n endiq ee hc th sh 6, it is diametrically slotted and-a fiat bar I of spring-;materia;l connects theinnerends of the twoshortshaftsfi, the ends of the flatbar 1318 ing' received the-slots, and bolts or other equiv alent connections used. In getter-a1 it is desir: able :that the connections be those which may be -clisconnected; suchfas bolts and nuts, for any repair or replacement of parts. At theouter projecting end of each of the shafts 6 anangle member is -"permanentlyasecured. It includes a vertical leg- =8 and"an integral1yextending generally horizontal'l'eg-t At the'inner side of the '1eg'='8*and* at itsupper portion a bar -10 is Welded :(or otherwise "apermanentlywecured. The associat'ed' shaft 6 *at "its "outer "end. .passes through thefrontend portion'of the bar' It and the like front endzpor'tion of the verticalweb 8. A wheel carrying a spindle 5 I I "is permanently "secured at 'the "rear end portions of *said-ibar l 0 and web 8 on whicha w'heel t2 isrmouhted for turning.

l3etwe'en"eaGh' Of th'eZbarS 1 8 and the outer end ofthe'sleevefbiishing fi a felt washer l3 islocated for 5 retaining lubricant within the bushing around the "shaft." A similar "Washer 14 "is :10- cated arol inii""the 's'h'a'ft *6 at the inner end of eac bushing *5 for 'the same'purpose; against which is ametiil' washer I 5, A coiled compr'es site-spri g i e {is 'around" each of 'the "shafts t 'at its" 'iri nr end ort'io'ri," and bears at *o'hef-ehd against the wa her 1'55 =At its "other or inner end-it is against alikewasher' t1 'hich is pressed 15 ;"the*sp ngfaganist'th' '-"adj cefit end of was *h vy c ed ctinpr ss on 3 may be connected by bolts to said plate and le as shown.

Each of the shafts B is turnable independently about its axis of turning and each one may be turned or rotated to a greater extent than the other to which it is connected by bar I in the same direction, or they may rotate in opposite directions. In either case the flat spring bar 1 is twisted or subjected to a longitudinal torsional strain. Said bar 1, which is of a good quality of spring steel, resists such torsional strain, but yields to the stress applied to it when it is greater than such resistance. Thus if one wheel should strike an obstruction in the road and rebound therefrom, its associated spring [8 first being heavily compressed and then elongated rapidly while the opposite wheel remains in frictional engagement with the road, it is evident that the bar 1 connecting the two shafts 6 will be torsionally distorted and will resist such distortion in accordance with its strength of resistance, thereby controlling the wheel which may have bounced upwardly so as to be out of contact with the road and holding it against excess movement to which it would have been subjected if the shaft 6 with which it is connected was entirely free to turn about its axis under the force supplied by the associated spring it. But such yielding connection between the two short shafts 6 allows a much greater freedom of action of either wheel connected to the outer ends of the shafts 6, and with a maintenance of stability approaching that which would be provided by a solid shaft taking the place of the two short shafts 6 and the connecting bar 1 between them.

It is of course to be understood that by lengthening the horizontal leg 9 and the frame members 3a, and correspondingly lengthening the plates 4, more than a single spring l8 may be used with each wheel.

The invention in use has proved very practical and useful and serves the purpose for which it was designed in an exceptionally satisfactory manner. The claims appended hereto define the invention, which is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. In a structure as described, a generally horizontal chassis frame having spaced parallel chassis side frame members, a horizontal sleeve permanently secured on and transversely of each of said chassis side frame members, said sleeves being located in axial alignment, a short shaft extending through each sleeve and .free for rocking movement therein, a flat bar of spring material extending between said shafts and connected at its ends to the inner ends of the shafts, an L-shaped member having a generally vertical flange and a generally horizontal inwardly extending flange at the lower end of the vertical flange at the outer end of each shaft, means connecting the outer end of each shaft to the vertical flange of its associated member adjacent an upper corner thereof, a wheel carrying spindle connected with the vertical flange of each of said members adjacent its opposite upper corner, a wheel on each spindle, and a coiled compression spring disposed between the frame and said inwardly extending flange for yieldingly resisting rotative movement of said member and attached wheel about the axis of its associated shaft.

2. A structure as defined in claim 1, and a lubricant retaining washer around each shaft between the outer end of each of said sleeves and the adjacent flange of its associated member, a second lubricant retaining washer around each of said shafts at the inner end of its associated sleeve, and spring means mounted on each shaft at the inner end portion thereof to yieldingly press the last mentioned washer against the inner end of its associated sleeve.

3. In a structure as described, a frame including two spaced apart generally horizontally chassis side frame members, a transverse crossbar connecting said side frame members, a short frame member spaced inwardly from each of the side frame members permanently connected at one end to said crossbar and extending therefrom parallel to its associated side frame member for a distance and then outwardly to said side frame member and permanently connected thereto, a horizontal plate secured to and extending between the upper portions of each chassis side frame member, and a horizontal sleeve extending through each chassis side frame member and associated short frame member, said sleeves being in horizontal alignment, 2. short shaft extending through each sleeve and free for rocking movement therein, a bar connecting the inner ends of said shafts and extending between them, said bar yieldingly resisting torsional strain, an L-shaped member having a vertical flange and an inwardly extending horizontal flange secured at the inner end of each shaft at the upper front corner portion of the vertical flange thereof, said horizontal flange extending under said horizontal plate, a. coiled compression spring between said horizontal flange and said plate, a wheel carrying axle permanently secured to said horizontal flange at its rear upper corner portion, and a wheel rotatably mounted on said spindle.

4. A structure as defined in claim 3, said horizontal flange at its inner side and upper portion having a horizontal bar located thereagainst and permanently secured thereto, the associated shaft and wheel spindle having permanent connection to both said bar and vertical flange of the associated member.

5. A structure as defined in claim 4, a washer around the shaft between said horizontal bar and the outer end of each sleeve, a second washer around the shaft at the inner end of each sleeve, said washer being of fabric material, a metal washer around each shaft lying against said second mentioned fabric washer, a coiled spring around the shaft having one end bearing against said metal washer, and a second metal washer around each shaft against which the other end of the spring engages, said second metal washer bearing against the adjacent end of said connecting bar between the shafts.

MATHEW D. SULLIVAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,137,720 Anderson Apr. 27, 1915 2,002,402 Konopka May 21, 1935 2,090,141 Newton Aug. 1'7, 1937 2,164,602 Valletta July 4, 1939 2,166,774 'Ijaarda July 18, 1939 FOREIGN PATENTS Number Country Date 798,613 France Mar. 10, 1936 

